A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation

Abstract

Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect patients from sudden cardiac death (SCD). However, inappropriate shocks may occur if tachycardias are misdiagnosed. Inappropriate shocks are harmful and impair patient quality of life. The risk of inappropriate therapy increases with lower detection rates programmed in the ICD. Single-chamber detection poses greater risks for misdiagnosis when compared with dual-chamber devices that have the benefit of additional atrial information. However, using a dual-chamber device merely for the sake of detection is generally not accepted, since the risks associated with the second electrode may outweigh the benefits of detection. Therefore, BIOTRONIK developed a ventricular lead called the Linox SMART S DX, which allows for the detection of atrial signals from two electrodes positioned at the atrial part of the ventricular electrode. This device contains two ring electrodes; one that contacts the atrial wall at the junction of the superior vena cava (SVC) and one positioned at the free floating part of the electrode in the atrium. The excellent signal quality can only be achieved by a special filter setting in the ICD (Lumax 540 and 740 VR-T DX, BIOTRONIK). Here, the ease of implantation of the system will be demonstrated.

Home monitoring report from a single lead Lumax DX implantable cardioverter defibrillator: New observations in a new system

“…Since the patient had normal sinus rhythm and normal atrio-ventricular conduction, a single lead, Biotronik, Lumax 640 VR-T DX ICD was selected. A DX system consists of a single lead, which provides atrial as well as ventricular electrograms, and enhances atrial arrhythmia detection [1] . The patient was followed-up in the clinic and via the home monitoring service.…”

Troubleshooting Implantable Cardioverter-Defibrillator Sensing Problems II

“…[18][19][20] However, data on sensing during rapidly conducted AF are scarce, and the only comparative study reported more atrial sensing problems with this method than a conventional atrial electrode (36% versus 11%; P=0.002).…”